Commercial Replacement - Before/After

Dan Foley

We recently replaced the hot water boiler and DHW water system in an apartment complex in Arlington. There are 8 low rise 52-unit buildings built in the 1940's. We replaced two of the systems in October and November. I hope we do the other six once they see the reduction in gas usage thus winter.

The building is heated by cast iron radiators on a steel Mono-Flo loop. The existing boilers were 1.2M BTU Smith cast iron boilers with Power Flame burners. They were wired to run at 180 whenever the outdoor temperature dropped below 60*. Cracked sections were replaced at least five or six times, including last December When I first surveyed the job in March, it was already cracked again.

DHW was produced by a 300k copper fin tube heater with two 80 gal storage tanks.

Dan Foley

In progress pictures of the piping.

Dan Foley

After:

We installed two Pure Fire 460 condensing boilers using the old chimney as a vent chase. Centrotherm makes a two-pipe kit that worked great. Combustion air is piped through the side wall allowing us to close up a 36" x 48" combustion air louver.

DHW is provided by a 120 gal Turbo Max.

A load calculation showed that the boilers were grossly over sized. We reduced input by almost 40%. Running lead/lag with full reset will increase comfort while reducing gas usage even more.

We also insulated all off the exposed mains with 1" fiberglass. The old asbestos had long been removed.

Dan Foley

Some pictures of the building and chimney.

EzzyT

Wow that is gorgeous, Dan you and your guys do some really neat work.

Dan Foley

Thanks, @ EzzyT.

Poppy and his crew did most of the work. Brian G helped with the design and start up.

Rich Michael from Peerless was so helpful with the initial start up. Above and beyond the call of duty. Jeff Riley with Coredron, the local rep, was also very helpful.

nicholas bonham-carter

Why we're the old sections cracking so often?--NBC

Dan Foley

Piped wrong. Pump was coming on with the boiler already at 180*. Cold return water causing thermal stress.

Mark Eatherton

Nice work Dan. Curious, did you build the new system while the old system was on line, or did you provide temporary DHW and space heat?

Brings back some (mostly) good memories of doing commercial MFD upgrades and replacements. Minimum savings was 30 % and high was 50%. It does require some re-education of residents, who were used to being able to crank up their thermostats and have heat puked all over their bodies...

Kudos to you and the crew. Great job.

ME

lchmb

How much do I have to pay to work for you? Nice, neat, serviceable and clean...

Dan Foley

@ lchmd, thanks!

@ Mark Eatherton

We got lucky with the weather. We had a mild fall here in DC. We did not provide temporary heat. Each system took 7-10 working days. With only a few chilly nights, we lucked out.

We could not cut off DHW for 10 days. We needed the chimney chase to pull the Centrotherm flex liners down. I thought about busting in a new flue crock into the abandoned incinerator chimney but Poppy came up with a better idea.

He removed the glazing from the basement window and installed a temporary plywood panel. He then vented the 10" Lochinvar DHW boiler vent through the plywood panel and ran it exposed approximately 15' up the outside wall. He confirmed that it was drafting and vented it this way during the two-week re-pipe.

After the boiler room was piped and the new system was operational, he did the DHW switch-over in one long day.

A.J.

WOW Dan you really set the bar high on that job.

Ironman

Nice job, Dan.

When I was a teenager, I lived a little over a mile from there up on Veitch St.

John Mills_5

Beautiful job!

Nice chiller too, how are they cooling the joint? Fan coils in each apartment?

Dan Foley

They have fan coils in each apartment.

I am hoping to do the chillers and pump stations over the winter.